Construction of dams and method of building same



NOV. 20

WITNESSES F. N. CRONHOLM CONSTRUCTION OF DAMS AND METHOD OF BUILDING SAME Filed March 14, 1922 4 Sheets-Sheet 1 ATTOR N EY Nov. 20, 1923'. 1,474,582

F. N. CRQNHOLM CONSTRUCTION OF DAMS AND METHOD OF BUILDING SAME V Ln WITNESSES ZMME I I ArronNw- Nov. 20 1923.

' I F. N. CRONHOLM CONSTRUCTION OF DAMS ANDMETHOD OF BUILDING SAME Filed Marbh 14 19.22 4 Sheets-Sheet 5 WITNESSES ATTORNEY Nov. 20,1923. 1,414,582 F. N. CRONHQLM CONSTRUCTION OF DAMS AND METHOD OF BUILDING SAME I w ssssss ES c v W BY k V I I NEY specification.

Patented Nov. 20, 1923.

FREDERICK 1\T. CBQNI-IOLM, or LOS Aives ns, oALiFoImI on m flon or DAM Ase Mere-01 meme Application filedMerchi, 1922. Serial No; 543,767.

To all whom it may concern:

' Be it known that I FZiEQERICK N. QR HO M, a citizen ofth e UnitedlStates; residr ing at Los Angeles, in the county of "Los s ngeles andfS tate of California; have in vented nex'v and useful Improvements in Construction of Dams and Methods of Building Same, o which the'tollowing is This'invention pertains to u the constructionot dams and especially to an improved method of building dams.

The object or" the invention is to provide an economical plan of constructingrlams and. novel method by which dams otany siyie may be built orlevees' constructed.

The invention contemplates the employment of dam elements, in the form of bundles or mattresses" which are buoyant and which, when anchored and held taut and subjected to the'fio'w .o't' the stream, are causedto nose or dive under at the up stream end and sink to and rest upon the bottom of the stream where they are held by the flow of water until the sand or silt curried down by the stream gathers upon the dam elements and finally .anchors them 211 place;

The invention "has various other objects which will he understoodfrom the following detailed description.

In the drawings which accompany and iorm a part of this speci;fi'cati on ,and where in severalillustrative embodiments of the invention are shown,

Figure l is a diagrammatic plan view showing the construction of a dam 'in accordance with the principles of this invention;

Figure 2 is across section through a river bed showing more or less schematically some ofthe darn elements and the method 'followed in placing said elements upon the bottom, and the manner of anchoring the same; Figure 3 is a transverse section through a river bed substantially on the line 3-3 of Figure 1; 1

Figure 4 is a plan view of a preferred form of dam element;

Figure 5 is a side elevation of the same; Figure 6 is a plan View of one of the frames used invconstructing the preferred tormot' element which go to make upa'dam according to my invention;

Figure 7 is an end elevation of the larger end 01? one of the dam elements;

' Figures 8 to 13 are somewhat diagrammati c views illustrating some 0f the fdr'lns which the imp noveld elements may sums and. also 'showil ig 'the followed "liiefe'rriiigmore specifically to the drawing to the illustrz ttive ,feinbodiiiient of my invention showri'thercin," there appears a body ofwater 15 "which may be considered to be a river flowing with a conslderable velocity, because the "invention is most easily carri'edout with such streams. T he inven. tion has been tried out onthe Colorad oltiv;

er and has proven successful damming the river where itis froni l 5 to itet' dee p' and approximatelyfiw' feet wide. Thedirection of the flow is i 'dicated the arrow iii all thenecessary figures. l i Into the bed 16 of th estreani, piles are driven to form dolphins 17, about 100 feet apart and toot or so above the surface otthe water at its highest level. The dolphins are used as a convenient but not indispensable means "for anchoring the dam "to be de scribed. In Figure 1 thercareshown towers 18 erecteduponopposite banks offthe river, and a cable 20 stretched btweeir's aid towers, Lines 21 anchor a barge 22 to the cable 20 so that the barge is held upstream relative to the site of the dain'andin cenveni e'nt positions to drive the: piles-"which m s up h d hins e b e emay be used in anchoring theda'm elements as so used; I

to the dolphins; "and in it shown ed directly above "the site' 'o fthe eiwy 3 1 PPQfte y see-en w rs 24 upon'the banks of the strea ,and an chored as at 25. SeeFigure'BC cableway is preferably used for 'sup 'po'rting' a,

ro ley e ploy d t qe y t e am t me to aiposition directlyabove the places where theyjai e to: be sunk. One form of a' dam unit is indicated at 27 in Figure 3 The specific construction of this unit or dam ele ment is shown in Figures Q5,

which reference is nowmadei' The dam elements or units employed in the practice o t my invention may assume a variety of shapes, but preferably are of some one of the shapes shownin ings. 'An an ular form gives the best results. It willbe understoodthat in" whatshar h 'e eri nts e t olmedeend i st? whatever materials, such elements are to be considered as within the scope of my invention,'-- provided they are included within one or more of the appended claims, or the claims of my (to-pending application, Serial No. 463,141, the claims herein being generic to the disclosed invention in both applications.

Each dam unit or element is preferably made of longitudinal beams 23 and cross beams 29 secured together: and constituting top and bottom frames. Spikes or bolts 30 and ropes, wires or cables 31 are shown as the preferred means by which the beams are held together, so that an interior filling 32, which may be of brush,-is held under more or less compression between the frames. The brush, which may be cut from along the banks of the stream which is to be dammed, may be first tied into bundles, and these bundles stacked lengthwise and crosswise in alternate layers, or in any other manner, which will give the dam element the desired compactness. In practice the dam units may be about ten feet wide, fourteen feet high at the back or downstream end, and thirty feet long, although units of widely varying dimensions may be used successfully in con structing dams.

In Figures 4: to 7 inclusive the dam elements are shown as having a wedge shape, and in the co-pending application to which reference has already been made, this specific shape enters into the claims. In the other figures of the drawing, no attempt has been made to indicate more than the outline of the dam elements, as this is considered unnecessary in view of the detailed illustration of the wedge-shaped form,

When the elements are made from timbers and brush they will be buoyant and may be floated into position above the dam site before being sunk to the bottom of the stream; but it will be understood that it lies within the scope of my invention to employ dam units which are heavier than water. I prefer to use bouyant elements, first, because the labor of handling them is little; second, the cost of making them is low; and third, the interstices of the brush with which they are filled become clogged with silt and sand brought down by the waters of the stream.

The preferred method of constructing a dam in accordance with my invention is briefly to anchor a series of dam elements from each dolphin so that a row, or several rows of elements, stretch across from bank to bank as shown in Figures 1 and 3; In order to anchor the elements, they are first trans ported to the place where they are to be sunk, as by being floated, or by means of the trolley 26. A cable 33 is attached to each unit before it is sunk, and a loop 34: is formed in the cable 33 so that when the loop is slipped over the dolphin the unit will be held directly over the spot where it is to rest (see Fig. The dam elements when made of bouyant material are sunk by making use of the force of the flowing stream acting on one of the sides or faces of the unit. The unit 27 may be held above the water by a cable 35 suspended from the trolley, and'a line 36 is attached to cable 35 so as to steady and guide the element into position. Both the line 36 and cable 33 are conveniently controlled from the barge 22. The element 27 is lowered until it floats in the water when it will assume approximately the position shown in Figure 8, and the swift flowing water aided by a pull on the cable 33 when it becomes taut will cause the element to oscillate about its center of gravity, and the upstream pointed end will dive or nose under the water and present the top surface of the element at an acute angle to the direction of flow of the stream. The resultant force derived from the kinetic energy of the flowing water is more than. sufficient to overcome the buoyancy of the element, and the force of the stream acting upon the inclined upper face of the element causes it to sink to the'bottom of the stream as shown in Figure- 8. 7

Once. upon the bed of the stream, the continued flow of the water and the anchoring cable 33 will hold the unit in position; in due time mud and silt will fill the interstices and cause the dam elements to become heavier than the water, and the units will remain anchored on the bottom and form substantially one homogeneous mass, providing a lasting barrier for the stream. If desired, a discharge pipe 37 leading from a suction dredge (not shown) may beused to deposit mud and sand at the dam site, so that the interstices of the dam elements may be more quickly filled. The weight of the units will increase as silt is accumulated so that shortly they will lose all their buoyancy; and the lowermost units will be pressed into the bed of the river.

The barge 22 is used not only for driving the piles forming the dolphins, but for placing the loops 39 of the cables 33 over the dolphins to anchor the dam elements.

In Figure 8 there is shown a buoyant wedge-shaped element 27 having cables 33 attached at each Side to the elementat a point 33 intermediate of the length of the element. This is the construction shown in my co-pending application. The element oscillates about the point of attachment 33 of the cables to the element, when the force of the water raises the downstream end of the element.

Figure 9. shows cable 38 secured to the top of the element at the downstream end and a cable 33 connected to the opposite and upstream end, both cables being looped about the dolphin. In this form the dam element oscillates f at the point of connection of the cable 38 with the downstream' end-and. this continues until the line 33-becomes taut,

1 of the element. 'is slightly. inclinedt'o. the

I horizontal.

I cables 38, 33 attached respectively to. the.

the invention the dam element must have a flat face or faces, and that the attachment The buoyant element'39 in Figure 10 has a rectangular. shapeand is'controlled by downstream and upstream ends of the unit. The force of the fiowingstream 1s against-the upstream end and. along the bottom: ofthe element. Being restrained from going'with. the flowby anchorage line 88, the element raises slightly on the downstream end, the front-end dips because the line 33 is slack, and the forceof the flow is transferred from the-bottom-and upstream end to the sloping .t o'p face, thus forcing the. element to sink to the bottom of the stream, as shown.

.Figure 11' shows an angular element 40 with six sides, but the upstream side is disposed at an'acute angle with the bottom of the element. The-cables 38 and 33are both connected to the upstream end at the top and bottom respectively." The force of the water striking against the inclined upstream face and along the bottom causes the lower end, to which theislack cable 33 is attached, to tip under, causing the same result as in the other forms.

In Figure 12 the dam element is a parallelogram. The cables38'f33 in Figure 12 are attached to theupstream face at the upper and lower edges respectively. In this form, the angle'of the upstream face of the dam element becomes greater to the stream the more the element submerges, The operation of this. form does. not differ from. the

. form shown in Figurell.

The element 397m Figure 13' has the, lines 33, 38 attached to the upperdownstream edge and to thelower upstream edge; Theelem'ent does: not-"'commence to submerge as soon as line 38 is taut, but begins whenline 33 is taut, after which the element proceeds to the bottom because of the force of the stream against the top face of the element.

It will be observed that in all forms of of the cable or cables thereto must be such that the-velocity of the stream strikes the 'element at an angle; or stated in other language, the mode of attachment of the cable causes a face of the element to become exposed to the flow of the stream at an angle which brings about the submerging of the'element. The angle of the element to the flow of the stream is predetermined by the varied length of the anchorage cables and by the manner of their attachment to the element.

What is claimed is 1. The method of constructing dams in flowing, streams, from dam elements having at least one flat face and which are buoyant at the time the dam is constructed, which consists in anchoring said elements in the stream against participation in the flow of the stream, and manipulating" said elements so. that the current strikes said; flat facesv at an angle and causes the upstream ends of the elementsto be depressedthereby in.

creasing, the resultant of forces due to the flow of the water acting against the upper faces of the elements, whereby said elements sink. tothe bottom ofwthe stream and remain there without the necessity of ballast being added thereto. a

2. The method of constructing dams of initially buoyant angular-shaped elements in flowing streams, which consists in anchon ing said elements in the stream against participation in the flow of the stream, andmoving the elements so that the resultant of forces due tothe flow of the stream will act against the elements and-cause them tobe depressed and sink in opposition. to their buoyancy until such elements rest upon'the bed of the stream.

3. The method of constructing dams of. initially buoyanteleinents havingat least one flat face in flowing streams, which consists in anchoring. said elements in the stream against participation in the flow of the stream, with the flat faces presented upstream, and moving the elements so that the resultant of forces. due to the-flow of the stream will counteract the buoyancy of the elements and cause themto be depressed and sink until such elements are arrested by the bed of the stream, and; maintaining the anchoring of the elements until sufficient foreign material has been deposited by the, steam in or upon the elements to overcome their buoyancy and maintain "them per manently resting on the stream bed independently'of the anchoring means. i

4:. The method of constructing dams win flowing streams, from buoyant elements of angular shape, which consists in locating anchoring means transversely of the stream in a line upstream from the dam site, transporting the elements to points directly over the dam site, connecting the elements to said anchoring means so that one fiat face of each element is presented to the velocity of the stream at an angle, whereby the'flow 0f 5. The method of constructing dams for flowing streams from a plurality of buoyant sented at an angle to the direction of flow of the stream, whereby the kinetic energy of the water forces the elements to dive to the bottom of the stream and remain there permanently.

6. The method of constructing dams in flowing streams, which consists in .anchoring angular-shaped buoyant elements with the inclined upper surfaces of the elements presented upstream, such anchoring being located at points further upstream than the site of the dam, in positions whereby the stream will overflow the elements and by reaction thereon depress said elements until their downward movement is arrested by engagement with the bed of the stream, to be there held by the continued reaction of the flowing water on the surfaces of the elements.

7 The method of constructing dams in flowing streams from buoyant dam elements of angular shape, which consists in locating said elements with the upper faces of the elements in an inclined position directed upstream, attaching anchoring means to an intermediate point of the upper surface of each element and at an angle thereto, whereby the reaction of the flow of the stream causes the depression of the elements in opposition to the buoyancy of said elements until the elements are pressed against the bottom of the stream, and maintaining the depression of the dam elements by the flow of the stream until said elements become permanently anchored by accumulations of material thereon.

8. In dam. construction, in combination,

a plurality of buoyant dam elements each.

formed froman upper frame and an interior filling and having at least one substantially remote points one in a higher plane than the other with one of the anchoring means, whereby the dam elements may be manipulated into a position such that the force of the flowing stream acts to cause said elements to sink to the stream bedwithout the use of ballast and remain there.

i 9. In dam construction, dolphins spaced upstream from the location of the dam, angular-shaped buoyant dam elements, separate cables secured at different points to each dam element, and anchored to the dolphins, one of said cables being located above the other, and the lower'cable being normally slack, whereby the force of the flowing stream causes said elements to tip and the upper faces of the elements to assume an inclined position to the flow of the stream, thereby tending to depress the elements in opposition to their buoyancy until such elements are arrested by the bed of the stream.

10. In dam construction, dolphins rising from the bed of the stream and spaced upstream from. the location of the dam, angular-shaped buoyant dam elements, and cables secured to the: dolphins and connected to the dam elements at two remote points of the latter and at an angle thereto, one of the two points being on a higher plane than the other so as to cause the upper face of the element to assume an inclined position with relation to the direction of flow of the stream, whereby the reaction of the force of the flow of the stream against the elements depresses the elements in opposition to the buoyancy thereof and causes them to, sink until such elements are arrested by the bed of the stream. I

In testimony that I claim the foregoing as my own, I have hereto aflixed my signature.

FREDERICK N. CRONHOLM.

the upstream end of 

